Quote:
Originally Posted by dougwilliams
So the actual problem was that the wiring from the PDP to the PCM was too small (I believe it was 18). When the compressor kicked it blew the fuse. We went to 16 and everything is fine. That seems like a fine line - but no blown fuses since.
|
Changing to a larger wire size should not prevent the fuse from blowing. For the short wire lengths used in FRC robots, the difference in wire resistance will not make a measurable difference in the current through your load. It is more likely that you had a "stray strand" in your old 18 AWG wire that was causing a short between the positive and negative terminals of the PCM. Those terminals are only 3.5mm apart, center-to-center (just a bit over 1/8 inch) so a stray strand can be difficult to see. You may want to use a bright light to visually inspect all of the connections on these small Weidmuller connectors on the PDP, VRM and PCM. Please note that these terminals alternate between positive and negative so it is possible to short between the positive terminal of one circuit to the negative terminal of an adjacent circuit.